Organizing phenomena

In this final chapter we will consider how the principles and techniques of KO can be applied in practice to the variety of knowledge resources. We start again with the first dimension of knowledge that is relevant to KO: classes of phenomena.

One simple need of human knowledge is to organize its objects into manageable groups, to be discussed and further examined. In all sciences an important component is what is variously called ‘systematics’, ‘taxonomy’ or ‘classification’ of the phenomena studied. In our review of KOS types we saw that the term taxonomies is often adopted for hierarchical systems of objects, such as plants, wines or cars, as distinguished from systems of document subjects (see section 4.4.2).

For example, systematic biology is the branch of biology dealing with the ordering, listing and nomenclature of the different kinds of organisms. Systematic biology produces hierarchical KOSs of animals, plants, fungi, etc. that are biological taxonomies. The term classification in this field is usually reserved to the act of identifying the species and the higher groups (taxa) to which a specimen belongs by inspecting its relevant characters (say, shape of leaves, number and color of petals, etc.) and comparing them with those of groups known in the literature.

Systematics often develops quite early in the history of a science. After some general description, the variety of objects needs to be organized at least in some provisional way in order to get a picture of the field. While animals and plants were already described by simple lists in antiquity, such phenomena as climates, soils or languages have started to be systematized only relatively recently. This is because such objects are more complex and need a greater effort to be defined, identified and compared: for example, while a giraffe is clearly different from an antelope, the dialects of Occitan are articulated systems of spoken sounds that need long research before being described and distinguished from those of Catalan (systematic work in linguistics is known as ‘typology’).

As work proceeds, groups of languages may be identified as part of more general categories, such as Romance languages, in turn grouped in Indo-European languages and so on: in this way a hierarchy of classes and subclasses is developed.